  .holder {
    position: relative;
    left: 35%; 
    top: 50%;
}
    .avatar {
      margin: 25px auto;
}
      img.user {
        height: 200px;
        width: 200px;
        background-color: #500000;
        box-shadow: 0 0 0 5px #500000 ;
        border-radius: 50%;
 }   
         img.user:hover {
          cursor: pointer; 
          -moz-animation:bounceOut .4s linear infinite;
          -webkit-animation:bounceOut .4s linear infinite;
        }
      

@-moz-keyframes bounceOut {
        0%{ box-shadow: 0 0 0 4px #500000; opacity:1;}
        25%{ box-shadow: 0 0 0 1px #500000; opacity:1;}
        50%{ box-shadow: 0 0 0 7px #500000; opacity:1; }
        75%{ box-shadow: 0 0 0 4px #500000; opacity:1;}
        100%{ box-shadow: 0 0 0 5px #500000; opacity:1;}
}

@-webkit-keyframes bounceOut {
        0%{ box-shadow: 0 0 0 4px #500000; opacity:1;}
        25%{ box-shadow: 0 0 0 1px #500000; opacity:1;}
        50%{ box-shadow: 0 0 0 7px #500000; opacity:1; }
        75%{ box-shadow: 0 0 0 4px #500000; opacity:1;}
        100%{ box-shadow: 0 0 0 5px #500000; opacity:1;}
}